Institute of Medicine Food and Nutrition Board Committee on Food Chemicals Codex Revised Monograph - Konjac Flour Please send comments to the Committee on Food Chemicals Codex, National Academy of Sciences, FO 3042, 2101 Constitution Avenue, N.W., Washington, DC 20418 or email them to
[email protected]. All comments must be received by December 15, 1996, for consideration for the First Supplement. ______________________________________________________________________________ June 13, 1996 Konjac Flour Konjac; Konnyaku; Konjac Gum; Yam Flour CAS: [37220-17-0] DESCRIPTION A hydrocolloidal polysaccharide obtained from the tubers of various species of Amorphophallus. Konjac Flour is a high molecular weight, nonionic glucomannan primarily consisting of mannose and glucose at a respective molar ratio of approximately 1.6:1.0. It is a slightly branched polysaccharide connected by b-1,4 linkages and has an average molecular weight of 200,000 to 2,000,000 daltons. Acetyl groups along the glucomannan backbone contribute to solubility properties and are located, on average, every 9 to 19 sugar units. The typical powder is cream to light tan in color. Konjac Flour is dispersible in hot or cold water and forms a highly viscous solution with a pH between 4.0 and 7.0. Solubility is increased by heat and mechanical agitation. Addition of mild alkali to the solution results in the formation of a heat-stable gel that resists melting, even under extended heating conditions. Functional Use in Foods Gelling agent; thickener; film former; emulsifier; stabilizer. REQUIREMENTS Identification A. Microscopic Test Stain about 0.1 g of the sample with 0.01% methylene blue powder in 50% isopropyl alcohol, and observe microscopically.